An image forming device including a cleaning device for removing foreign matter (e.g. developer) from the belt has been proposed. For example, in the image forming device of Japanese Unexamined Patent Application Publication 2001-56612, a belt (dielectric belt 1) is circulated around a pair of rollers, one of which functions as a drive roller, which receives motive force and rotates, causing the belt to rotate in one direction. A cleaning member is provided which contacts the outer surface of this belt and allows cleaning of the belt to be performed by causing the cleaning member to act as a load against the movement of the belt.
If one attempts to remove foreign matter by bringing a cleaning member into contact as a load on the belt, as in Japanese Unexamined Patent Application Publication 2001-56612, the contact load generates a force against the belt in the direction opposite to the direction of travel. This force causes slack to form in the belt. If slack is formed in the belt in this manner, defects such as racing of the drive roller may occur.